Translation for the notes above, starting from the top left in clockwise order:
The pupils and nose (especially the former) look a bit too brown. Try to make them blacker.
Having a single mountain in the background looks like a specific mountain, say Mt. Coronet or Mt. Fuji. It’d be better to have a more generic mountain range.
This part of the mane would probably look better if it were fluffier.
The rear leg should probably be visible from here.
The stripes on its fur should probably be visible here.
The ear to your left should be a bit longer. (Think of it as a squashed parallelogram.)
You should be able to see its fangs when Arcanine’s mouth is closed.
Maybe you could make the separate digital pads on the right rear paw.
Seeing the feedback given was definitely super interesting, especially the comments about tiny details of the Pokemon itself (e.g. spikier mane, more slender ear, etc.).
I thought the article was interesting. I wonder if they hold different artist to different standards or styles, and how the standard is determined . Komiya certainly does not meet a strict criteria in “this is how a Pokemon looks like”. As others point out there is a lot of variation in representing a Pokemon. Personally I like that.